Coming, a simple digital I/O test card for the Z50Bus

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Jon Langseth

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Jun 28, 2018, 2:43:22 PM6/28/18
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I still haven't sorted out the logistics of parts, and I haven't had the "final beta" PCB made and tested yet, but I wanted to put out a teaser of an upcoming addon:
A simple 8-bit digital I/O card!


This is not a card that allows connections to outside electronics, but a simple card where inputs may be given using push-buttons or DIP-switches, and output is presented on LEDs. The card uses a single IO address, selectable in the entire 8-bit range using the Address select DIP switches. This is a fairly large card considering what's on it, and could naturally have been smaller. The size is a full 100x100mm, and is an example of the typical size of a "standard-size" Z50Bus card.

Since then, a pre-production PCB has been spun, and I've made some adjustments. The pre-production PCB was designed for SIP resistor packs, but I went back to standard axial resistors to simplify logistics, reduce my part-catalog, and to make it "parts-bin pcb-only" friendly. Cost-wise axial resistors and SIPs would have been fairly similar in volume (8x 1 resistor vs 1x respack is about the same price).

I expect there to be some feedback on the design, but should warn you that I am very close to ordering the boards, and this was a product that was supposed to be available around the first week of june... On the other hand, this card is open sourced from the start, with the KiCad source files available already at https://github.com/linc80/Z50IOCard

Speaking of dates. I expect to have a three-week lead-up to having the card available. If all goes well, I should have connectors and PCBs for the ROM-cartridge kits available around the same time, so all three products will "launch" at the same time.

-- 
Jon Langseth - Proprietor of LiNC - http://linc.no

Jon Langseth

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Aug 18, 2018, 3:56:21 PM8/18/18
to LiNC80
In preparation of going live with a few new products, I'd like to inform about some updated files.
I am currently waiting on the approval process for the Digital I/O card mentioned in the parent post, as well as the long awaited ROM Cartridge kit.

I have posted a product page for the Digital I/O card at http://linc.no/products/z50bus-simple-digital-i-o-card/
The schematic and board-layout files have been updated at https://github.com/linc80/Z50IOCard
The assembly manual can be downloaded from http://linc.no/dl/linc80/doc/Z50IOCard-Assemblyguide%20v%200.1.pdf

I have posted a product page for the ROM Cartridge kit at http://linc.no/products/linc80-rom-cartdrige-slot-kit/
The schematic and board-layout files are available at https://github.com/linc80/SBC1-ROMCartridge

Next two products in the pipeline are an integration-friendly version of the Digital I/O card (one without the LED's and buttons, but headers and a prototyling-area in their place) and (much more exciting) a Soundcard based on the trusty and well-known AY3-8910/YM2149. I really hope to have a shorter time to release on those. The sound-card warrants it's own post when time comes :)

Jon Langseth

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Aug 19, 2018, 2:24:21 PM8/19/18
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The Z50Bus Simple digital I/O Card is now live on Tindie!


This simple 8-bit digital I/O card adds demonstration of hardware I/O to a Z50Bus compatible system, like the LiNC80 SBC1. It provides 8 lines of digital output controlling 8 LEDs, and 8 lines of digital input via pushbuttons and/or a DIP switch. The card is intended to be used for learning digital I/O, and for demonstrating simple I/O operations.

The I/O card occupies a single I/O address. The address of the card can be fully selected as any one address value in the range 0x00 to 0xFF. Writes to the selected address will be latched as output, driving the 8 LEDs on the card. Reads from the selected address is taken immediately from the combined state of the input DIP and pushbuttons. The buttons have pull-down resistors in their passive/off state, and the buttons and the DIP switches are connected in parallel.

A proficient user that wants to use this card to connect to the “outside”, may choose to omit the buttons and LEDs. A connector J2 is provided to allow easy connection of inputs. Each LED position has an indicating marker for Pin2/anode, which corresponds to the Output signal pin from the 74xx273 chip on the card.

Available as full kit, or PCB only.
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